From patchwork Wed May 24 18:18:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Simmons-Talbott X-Patchwork-Id: 69991 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id A61793857006 for ; Wed, 24 May 2023 18:18:59 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A61793857006 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1684952339; bh=sr/Rwn1PM63nZNFnY2rB2EOuWVmulDjQaYiyl4B0Ybs=; h=To:Cc:Subject:Date:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=piW/OrbmxjXIOKLLtFnw75uNqUyr3li8oA24fSn5Im4TakgfCy7xYycNqFYv3lRo9 sNVFqaUWapesFgZqW1vUOCX3Idg8krVBHPnXfc7r01RNlnb+fWdKqUmbanY+RwJEHA L70ZMkH6bWA/kK2K8lhYAHr40x1dB+K5hpxn+nYk= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 391A63858D28 for ; Wed, 24 May 2023 18:18:37 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 391A63858D28 Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-516-Tg7q3_HyNJWHCMFyESnmHA-1; Wed, 24 May 2023 14:18:35 -0400 X-MC-Unique: Tg7q3_HyNJWHCMFyESnmHA-1 Received: by mail-qv1-f69.google.com with SMTP id 6a1803df08f44-616731c798dso415796d6.1 for ; Wed, 24 May 2023 11:18:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684952315; x=1687544315; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=sr/Rwn1PM63nZNFnY2rB2EOuWVmulDjQaYiyl4B0Ybs=; b=TPNoWLRbCHUZqYbrpH/wANaKDJnRdT3tAZa5c2t9DwPNp/1VgF5JWwsbP09MJ5n1K6 lxdrOSk56bGJ1ijLPCrANrO3U9n0tzvUtjMyrA322/dYUiFfUTRHJFmqH2F2HPgULbOV 6cMk0Z0Lq0AMitXRfrWSnzm3bAgCLE3hfLq+iziiUWZhReckSyFD8MHtrhBZ0SUjljDK U3mklua/BeIiK0o3NQ77UFKqqMWSyDjerDHieuLM4Zhud+MiPjxhFl/R6yZVM0IU7Sbc Spo4q9T9dnpUMwFz+ghdg81S9xjBk/4SpH4CO/jSYM8GyTuibCgsIpNeZdmVJHdXmxgZ NzRw== X-Gm-Message-State: AC+VfDyX5JsDTAZRtNmREGvaQvEaisy0TaxPwNKlKBNHbsfRVUyDTFoC zFs5k06iIJuh0jIgn0KMAbQky8l3Zwr9LxlmWJzL97KGyUCL+JMQhLgAui8kutqdd7e4hO/PuEj dkjWP7JUz66BtUWwCJOWJApyH/2SvWF3sTrdZqXmCD6Ea9te/n56gjig7a62N9kSR2wtdAEKofm IWbgGV X-Received: by 2002:a05:6214:c82:b0:5f1:6a6a:f566 with SMTP id r2-20020a0562140c8200b005f16a6af566mr249139qvr.19.1684952314914; Wed, 24 May 2023 11:18:34 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ42wNhf6tKIeEssvgxur5qHTD7DyU9xoZxuQDs1BZu5aychnntZDLKOC/YqR+xCx8slo1mq2w== X-Received: by 2002:a05:6214:c82:b0:5f1:6a6a:f566 with SMTP id r2-20020a0562140c8200b005f16a6af566mr249124qvr.19.1684952314628; Wed, 24 May 2023 11:18:34 -0700 (PDT) Received: from oak.redhat.com (c-71-206-142-238.hsd1.va.comcast.net. [71.206.142.238]) by smtp.gmail.com with ESMTPSA id o8-20020a0ccb08000000b00621268e14efsm3735280qvk.55.2023.05.24.11.18.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 May 2023 11:18:33 -0700 (PDT) To: libc-alpha@sourceware.org Cc: Joe Simmons-Talbott Subject: [PATCH] setipv4sourcefilter: Avoid using alloca. Date: Wed, 24 May 2023 14:18:31 -0400 Message-Id: <20230524181831.41099-1-josimmon@redhat.com> X-Mailer: git-send-email 2.40.0 MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Joe Simmons-Talbott via Libc-alpha From: Joe Simmons-Talbott Reply-To: Joe Simmons-Talbott Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Use a scratch_buffer rather than alloca/malloc to avoid potential stack overflow. Reviewed-by: Siddhesh Poyarekar --- sysdeps/unix/sysv/linux/setipv4sourcefilter.c | 24 ++++++------------- 1 file changed, 7 insertions(+), 17 deletions(-) diff --git a/sysdeps/unix/sysv/linux/setipv4sourcefilter.c b/sysdeps/unix/sysv/linux/setipv4sourcefilter.c index 7f146d789a..8c77ba33bd 100644 --- a/sysdeps/unix/sysv/linux/setipv4sourcefilter.c +++ b/sysdeps/unix/sysv/linux/setipv4sourcefilter.c @@ -16,12 +16,12 @@ License along with the GNU C Library; if not, see . */ -#include #include #include #include #include #include +#include #include @@ -33,17 +33,12 @@ setipv4sourcefilter (int s, struct in_addr interface, struct in_addr group, /* We have to create an struct ip_msfilter object which we can pass to the kernel. */ size_t needed = IP_MSFILTER_SIZE (numsrc); - int use_alloca = __libc_use_alloca (needed); - struct ip_msfilter *imsf; - if (use_alloca) - imsf = (struct ip_msfilter *) alloca (needed); - else - { - imsf = (struct ip_msfilter *) malloc (needed); - if (imsf == NULL) - return -1; - } + struct scratch_buffer buf; + scratch_buffer_init (&buf); + if (!scratch_buffer_set_array_size (&buf, 1, needed)) + return -1; + struct ip_msfilter *imsf = buf.data; imsf->imsf_multiaddr = group; imsf->imsf_interface = interface; @@ -53,12 +48,7 @@ setipv4sourcefilter (int s, struct in_addr interface, struct in_addr group, int result = __setsockopt (s, SOL_IP, IP_MSFILTER, imsf, needed); - if (! use_alloca) - { - int save_errno = errno; - free (imsf); - __set_errno (save_errno); - } + scratch_buffer_free (&buf); return result; }